Simulation of the Effects of an Air Blast Wave - ELSA - Europa

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The corresponding TNT-equivalent is divided by the TNT equivalent of the overpressure. Thisdivision gives a value α bub shown in Figure 42. This value α bub shows a linear dependency also fordifferent sizes of the bubble, tested here with the radius of 0.5 m and 1.0 m. With this straight line itshould be possible to calculate an overpressure for a bubble with the volume V bub for a given chargeof TNT. The idea is to describe an equation with the following formp = f( V , W)(23)The equation of the line in Figure 42 can be described by this trend linebubbubα = −0.263⋅ log( p ) + 2.41(24)bubTNT1Energy of overpressure/Energy resulting pressure wave0.80.60.40.2lbub=0.5 mlbub=1.0 m06 6.2 6.4 6.6 6.8 7 7.2 7.4Pressure = energy of the corresponding TNT equivalent [log Pa]Figure 42: Factor α bubThe following procedure can be used to get the overpressure of the bubble for a given TNTequivalent.1. Calculation of the energy of the detonation withe = W ⋅ 4520 kJ / kg(25)2. Calculation of the overpressure energy of this amount of TNT withTNTpe( γ 1)TNTTNT= ⋅ − (26)Vbub56
3. Calculation of the factor α bub with equation (24).4. The pressure of the bubble can be calculated withppTNTbub= + p0(27)αbub5. The values for the internal energy e int,bub and the density ρ bub can be calculated bymultiplying the values of the uncompressed air with the factor f bubfpbubbub= (28)p0With this method it is possible to calculate by a given bubble size and a given charge theoverpressure in the bubble.57
Page 1 and 2:
Simulation of the Effectsof an Air
Page 3 and 4:
Distribution ListLechner S.Anthoine
Page 5 and 6: 1 IntroductionThis work is being co
Page 7 and 8: • Far zone. The blast wave result
Page 9 and 10: Figure 2: Model of Kingery [14] wit
Page 11 and 12: 2.2.3 ImpulseThe impulse of the air
Page 13 and 14: Figure 5: Different parameters for
Page 15 and 16: 250200Impulse from KingeryImpulse w
Page 17 and 18: the specific heat ratio and the spe
Page 19 and 20: determined with a fluid pre-calcula
Page 21 and 22: From this asymptotic form it can al
Page 23 and 24: 2.0E+101.6E+10without burn mass fra
Page 25 and 26: Case opening d pyra d ex,in d ex,en
Page 27 and 28: Pressure [Pa]2.4E+102.0E+101.6E+101
Page 29 and 30: 5.0E+094.0E+09EUROPLEXUS x=0.105EUR
Page 31 and 32: Cased pyr /d ex,in /d ex,end /d air
Page 33 and 34: Figure 21: Comparison of a coarse w
Page 35 and 36: CON9This model has approximately th
Page 37 and 38: 4E+7Max. pressure [Pa]3E+72E+7Kinge
Page 39 and 40: Case Size of the model Description
Page 41 and 42: CUB4This model uses a finer mesh th
Page 43 and 44: 6. Complete the volumes by adding t
Page 45 and 46: Figure 33: Maximum pressures versus
Page 47 and 48: experimental values is obtained wit
Page 49 and 50: 4.6.3 Arrival TimeThe arrival time
Page 51 and 52: value in [13]). These results show
Page 53 and 54: Modell airl bBubbleBubbleBubbleTNT
Page 55: Several calculations are done with
Page 59 and 60: quadratic. Therefore, the size of t
Page 61 and 62: 400Impulse [Pa sec]300200.Kingery 5
Page 63 and 64: 5 = hemispherical detonation (half
Page 65 and 66: 9 References[1] Alia, A.; Souli, M.
Page 67 and 68: 10 Apendix10.1 EUROPLEXUS Codedyms.
Page 69 and 70: CALLMECVAL(GET_FMT(6),NEWMAT%MATVAL
Page 71 and 72: 10.2 Miscellaneous codeairblastresu
Page 73 and 74: else{ //Kingerydouble t=log10(z);do
Page 75 and 76: maxar=0;REPE I0 (NBEL vges);ar = as
Page 77 and 78: *defining the surfaces around the a
Page 79 and 80: lpyr1 = p1 d ppy2;lpyr2 = p1 d ppy3
Page 81 and 82: lpyr2 = p1 d ppy3;lpyr3 = p1 d ppy4
Page 83: *Cube intermediaire (centre=o0 et a
Page 86: The mission of the JRC is to provid
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Simulation of the Effects of an Air Blast Wave - ELSA - Europa

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